There's a great moment of insolence from Scarlett Johansson in the movie that made her name - a moment that really endears you to a young performer. About halfway through The Horse Whisperer (note: I am not here to defend my sad and ineradicable fondness for three-hankie sob-fests - so back off), Scarlett has lost a leg in a riding accident, and has been brought out west by her distant and lonely rich-yuppie mother.

The mother-daughter relationship is the most rewarding, complicated and volatile in the movie - they're arguing in their motel room when the great moment arrives. There's a knock at the door and Scarlett swings it open yelling, "Yeah - whaaat?!" And it's Bob Redford, who so far, as director, has been doing a nice skilful job of not getting in the way of his actors. This is where he gets up off his directing stool, walks into the movie as an actor, and ruins it. Standing at the motel door, Scarlett looks at him with searing contempt and says, "Oh, it's YOU..." as if she knows that the fun has just ended. And as a performer she surely knows that Redford the thesp isn't fit to kiss her 13-year-old ass. That's what her face says to me.

Manny & Lo, which she made even earlier, aged 12, was the first movie that got Johansson noticed. She played a smart 12-year-old on the lam with her useless pregnant sister and the movie, a hit-and-miss indie, showed her as a fat-faced, gawky-looking odd-duck sort of kid with an extraordinarily deep voice. She's since grown into the face and the nose, and the voice is now a real asset - a throaty growl that may keep the bimbo roles away.

Since the success of Lost In Translation, Johansson has been cursed with the kind of overexposure that could kill a less hardy talent. She's done commercials, print ads, tabloid catnip ("Benicio Del Toro sodomised me in an elevator" was one lie that found traction), but the movies are reasonably well chosen. Girl With A Pearl Earring went the arty way, while the teen-heist comedy The Perfect Score was a rare venture into the kind of material that actors of her age must do to eat (she doesn't need to). In Good Company (pictured) casts her as an ingenue - Dennis Quaid's daughter, no less - and it will do until she stretches herself again. A forthcoming adaptation of James Ellroy's The Black Dahlia looks promising, while Mission: Impossible 3 does not. Fingers crossed, another smart young actress with better taste than most keeps her brain involved and her wallet open-minded.

Career high: The Horse Whisperer, Manny & Lo, Ghost World

Career low: Home Alone 3

Need to know: Auditioned for Disney's Parent Trap remake; the part went to Lindsay Lohan. Small world.

The last word: "I'm so tired of hearing casting directors ask if I have a sore throat."